Method and apparatus for relay backhaul design in a wireless communication system

ABSTRACT

Systems and methodologies are described herein that facilitate techniques for design of relay backhaul to support mobility of relay nodes in a wireless communication system. According to various aspects herein, techniques are provided to enable and support the use of mobile relays and to facilitate handover of mobile relays between respective donor cells. More particularly, techniques are provided herein for relay backhaul control channel assignment associated with hand in or hand out of mobile relays, access/backhaul resource partitioning for mobile relays, and management of quality of service (QoS) requirements associated with a relay handover.

CROSS-REFERENCE

This application claims the benefit of U.S. Provisional Application Ser.No. 61/233,270, filed Aug. 12, 2009, and entitled “SYSTEMS AND METHODSOF RELAY BASE STATION BACK HAUL.” Additionally, this application isrelated to co-pending U.S. patent application Ser. No. 12/853,835, filedAug. 10, 2010, and entitled “METHOD AND APPARATUS FOR RELAY BACKHAULDESIGN IN A WIRELESS COMMUNICATION SYSTEM.”The above applications areincorporated herein by reference in their entirety.

BACKGROUND

I. Field

The present disclosure relates generally to wireless communications, andmore specifically to techniques for managing mobility of relay nodes ina wireless communication environment.

II. Background

Wireless communication systems are widely deployed to provide variouscommunication services; for instance, voice, video, packet data,broadcast, and messaging services can be provided via such wirelesscommunication systems. These systems can be multiple-access systems thatare capable of supporting communication for multiple terminals bysharing available system resources. Examples of such multiple-accesssystems include Code Division Multiple Access (CDMA) systems, TimeDivision Multiple Access (TDMA) systems, Frequency Division MultipleAccess (FDMA) systems, and Orthogonal Frequency Division Multiple Access(OFDMA) systems.

Generally, a wireless multiple-access communication system cansimultaneously support communication for multiple wireless terminals. Insuch a system, each terminal can communicate with one or more basestations via transmissions on the forward and reverse links. The forwardlink (or downlink) refers to the communication link from the basestations to the terminals, and the reverse link (or uplink) refers tothe communication link from the terminals to the base stations. Thiscommunication link can be established via a single-in-single-out (SISO),multiple-in-signal-out (MISO), or a multiple-in-multiple-out (MIMO)system.

In various wireless communication systems, relay nodes and/or othersuitable network nodes can be utilized to enhance communication betweenan Evolved Node B (eNB) and respective user equipment units (UEs) servedby the eNB. For example, in the case of Hybrid Automatic Repeat Request(HARM) transmission and/or another suitable repeat transmission scheme,a relay node can detect communication between an eNB and UE and assiston re-transmissions to the UE as required.

Moreover, in some network implementations, relay nodes can be configuredto be mobile, where a mobile relay node can pass between respective eNBsto provide substantially continuous communication service for respectiveUEs associated with the relay node. However, if a relay node experiencesproblems during a handoff procedure from a source eNB to a target eNB,service degradation to the associated UEs, up to and including fullservice interruption, can occur. Accordingly, it would be desirable toimplement techniques for managing mobility of a relay node throughout awireless communication system with minimal impact on associated users.

SUMMARY

The following presents a simplified summary of various aspects of theclaimed subject matter in order to provide a basic understanding of suchaspects. This summary is not an extensive overview of all contemplatedaspects, and is intended to neither identify key or critical elementsnor delineate the scope of such aspects. Its sole purpose is to presentsome concepts of the disclosed aspects in a simplified form as a preludeto the more detailed description that is presented later.

According to an aspect, a method is described herein. The method cancomprise obtaining information relating to an access/backhaul resourcepartitioning corresponding to an associated relay node; detectingrequested handover of the associated relay node to a target cell; andindicating the access/backhaul resource partitioning to the target cellin connection with the requested handover to enable partitioning ofaccess resources and backhaul resources at the target cell based on theaccess/backhaul resource partitioning.

A second aspect described herein relates to a wireless communicationsapparatus, which can comprise a memory that stores data relating to arelay node and an access/backhaul resource partitioning corresponding tothe relay node. The wireless communications apparatus can furthercomprise a processor configured to detect requested handover of therelay node to a target cell and to indicate the access/backhaul resourcepartitioning to the target cell in connection with the requestedhandover.

A third aspect relates to an apparatus, which can comprise means foridentifying access resources and backhaul resources corresponding to arelay node and means for indicating identities of the access resourcesand the backhaul resources to a target cell corresponding to a requestedhandover of the relay node.

A fourth aspect described herein relates to a computer program product,which can include a computer-readable medium that comprises code forcausing a computer to identify access resources and backhaul resourcescorresponding to a relay node and code for causing a computer toindicate identities of the access resources and the backhaul resourcesto a target cell corresponding to a requested handover of the relaynode.

A fifth aspect herein relates to a method operable in a wirelesscommunication system. The method can comprise detecting requestedhandover of a relay node from a source cell; receiving information fromthe source cell in connection with the requested handover relating to anaccess/backhaul resource partitioning utilized by the source cell forthe relay node; and configuring an allocation of access subframes andbackhaul subframes corresponding to the relay node based at least inpart on the information received from the source cell.

A sixth aspect described herein relates to a wireless communicationsapparatus, which can comprise a memory that stores data relating to arelay node, a source cell, and a requested handover of the relay nodefrom the source cell. The wireless communications apparatus can furthercomprise a processor configured to receive information from the sourcecell in connection with the requested handover relating to anaccess/backhaul resource partitioning utilized by the source cell forthe relay node and to determine an allocation of access subframes andbackhaul subframes corresponding to the relay node based at least inpart on the information received from the source cell.

A seventh aspect relates to an apparatus, which can comprise means forreceiving information from a source eNB in response to a requestedhandover of a relay node from the source eNB relating to a partitioningof access resources and backhaul resources utilized by the source eNBfor the relay node and means for allocating access resources andbackhaul resources for the relay node based at least in part on theinformation received from the source eNB.

An eighth aspect described herein relates to a computer program product,which can include a computer-readable medium that comprises code forcausing a computer to receive information from a source eNB in responseto a requested handover of a relay node from the source eNB relating toa partitioning of access resources and backhaul resources utilized bythe source eNB for the relay node and code for causing a computer toallocate access resources and backhaul resources for the relay nodebased at least in part on the information received from the source eNB.

According to a ninth aspect, a method is described herein. The methodcan comprise identifying an allocation of access subframes and backhaulsubframes associated with relay communication; initializing a handoverfrom a source eNB to a destination eNB; obtaining information relatingto an access/backhaul subframe allocation utilized by the destinationeNB; and adjusting one or more subframes in the allocation of accesssubframes and backhaul subframes based on the access/backhaul subframeallocation utilized by the destination eNB.

A tenth aspect described herein relates to a wireless communicationsapparatus, which can comprise a memory that stores data relating to asource eNB and a destination eNB. The wireless communications apparatuscan further comprise a processor configured to identify an allocation ofaccess subframes and backhaul subframes associated with relaycommunication, to initialize a handover from the source eNB to thedestination eNB, to obtain information relating to an access/backhaulsubframe allocation utilized by the destination eNB, and to adjust oneor more subframes in the allocation of access subframes and backhaulsubframes based on the access/backhaul subframe allocation utilized bythe destination eNB.

An eleventh aspect relates to an apparatus, which can comprise means foridentifying an allocation of access resources and backhaul resourcesassociated with relay communication; means for initializing a relayhandover to a target cell; and means for adjusting at least a portion ofthe allocation of access resources and backhaul resources based on anaccess/backhaul resource partitioning associated with the target cell.

A twelfth aspect described herein relates to a computer program product,which can include a computer-readable medium that comprises code forcausing a computer to identify an allocation of access resources andbackhaul resources associated with relay communication; code for causinga computer to initialize a relay handover to a target cell; and code forcausing a computer to adjust at least a portion of the allocation ofaccess resources and backhaul resources based on an access/backhaulresource partitioning associated with the target cell.

A thirteenth aspect herein relates to a method operable in a wirelesscommunication system. The method can comprise detecting a requestedinitialization of communication service for a relay node in associationwith a handover of the relay node; identifying a quality of service(QoS) requirement for the handover of the relay node; and directingcommunication in connection with the handover of the relay node suchthat the QoS requirement for the handover of the relay node issubstantially preserved.

A fourteenth aspect described herein relates to a wirelesscommunications apparatus, which can comprise a memory that stores datarelating to a relay node. The wireless communications apparatus canfurther comprise a processor configured to detect requestedinitialization of communication service for the relay node inassociation with a handover of the relay node, to identify a QoSrequirement for the handover of the relay node, and to directcommunication in connection with the handover of the relay node suchthat the QoS requirement for the handover of the relay node issubstantially preserved.

A fifteenth aspect relates to an apparatus, which can comprise means fordetecting initialization of a handover of a relay node and a QoSrequirement associated with the handover of the relay node and means formanaging communication relating to the handover of the relay node suchthat the QoS requirement associated with the handover of the relay nodeis substantially met.

A sixteenth aspect described herein relates to a computer programproduct, which can include a computer-readable medium that comprisescode for causing a computer to detect initialization of a handover of arelay node and a QoS requirement associated with the handover of therelay node and code for causing a computer to manage communicationrelating to the handover of the relay node such that the QoS requirementassociated with the handover of the relay node is substantially met.

According to a seventeenth aspect, a method is described herein. Themethod can comprise initializing a relay handover to a target donor eNB;identifying a QoS requirement for the relay handover; and directingcommunication in connection with the relay handover such that the QoSrequirement for the relay handover is substantially preserved.

An eighteenth aspect described herein relates to a wirelesscommunications apparatus, which can comprise a memory that stores datarelating to a target donor eNB. The wireless communications apparatuscan further comprise a processor configured to initialize a relayhandover to the target donor eNB, to identify a QoS requirement for therelay handover, and to direct communication in connection with the relayhandover such that the QoS requirement for the relay handover issubstantially preserved.

A nineteenth aspect relates to an apparatus, which can comprise meansfor identifying a target cell for a relay handover and a QoS requirementassociated with the relay handover and means for managing communicationrelating to the relay handover such that the QoS requirement associatedwith the relay handover is substantially met.

A twentieth aspect described herein relates to a computer programproduct, which can include a computer-readable medium that comprisescode for causing a computer to identify a target cell for a relayhandover and a QoS requirement associated with the relay handover andcode for causing a computer to manage communication relating to therelay handover such that the QoS requirement associated with the relayhandover is substantially met.

To the accomplishment of the foregoing and related ends, one or moreaspects of the claimed subject matter comprise the features hereinafterfully described and particularly pointed out in the claims. Thefollowing description and the annexed drawings set forth in detailcertain illustrative aspects of the claimed subject matter. Theseaspects are indicative, however, of but a few of the various ways inwhich the principles of the claimed subject matter can be employed.Further, the disclosed aspects are intended to include all such aspectsand their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a system that facilitates operation ofmobile relay nodes within a wireless communication system in accordancewith various aspects.

FIGS. 2-3 are block diagrams of respective systems for resourceassignment for a relay node in connection with a relay handover inaccordance with various aspects.

FIG. 4 is a block diagram of a system for configuring a resourcepartitioning utilized by a relay node in connection with a relayhandover in accordance with various aspects.

FIG. 5 illustrates an example subframe configuration that can beutilized by various devices in a wireless communication system.

FIG. 6 is a block diagram of another system for configuring a resourcepartitioning utilized by a relay node in connection with a relayhandover in accordance with various aspects.

FIG. 7 is a block diagram of a system for maintaining required QoSassociated with a relay handover in accordance with various aspects.

FIGS. 8-14 are flow diagrams that illustrate respective methods formanaging mobility of a relay node within a wireless communicationenvironment.

FIGS. 15-21 are block diagrams of respective apparatuses that facilitatecoordination of a relay node handover within a wireless communicationsystem.

FIG. 22 illustrates a wireless multiple-access communication system inaccordance with various aspects set forth herein.

FIG. 23 is a block diagram illustrating an example wirelesscommunication system in which various aspects described herein canfunction.

DETAILED DESCRIPTION

Various aspects of the claimed subject matter are now described withreference to the drawings, wherein like reference numerals are used torefer to like elements throughout. In the following description, forpurposes of explanation, numerous specific details are set forth inorder to provide a thorough understanding of one or more aspects. It maybe evident, however, that such aspect(s) may be practiced without thesespecific details. In other instances, well-known structures and devicesare shown in block diagram form in order to facilitate describing one ormore aspects.

As used in this application, the terms “component,” “module,” “system,”and the like are intended to refer to a computer-related entity, eitherhardware, firmware, a combination of hardware and software, software, orsoftware in execution. For example, a component can be, but is notlimited to being, a process running on a processor, an integratedcircuit, an object, an executable, a thread of execution, a program,and/or a computer. By way of illustration, both an application runningon a computing device and the computing device can be a component. Oneor more components can reside within a process and/or thread ofexecution and a component can be localized on one computer and/ordistributed between two or more computers. In addition, these componentscan execute from various computer readable media having various datastructures stored thereon. The components can communicate by way oflocal and/or remote processes such as in accordance with a signal havingone or more data packets (e.g., data from one component interacting withanother component in a local system, distributed system, and/or across anetwork such as the Internet with other systems by way of the signal).

Furthermore, various aspects are described herein in connection with awireless terminal and/or a base station. A wireless terminal can referto a device providing voice and/or data connectivity to a user. Awireless terminal can be connected to a computing device such as alaptop computer or desktop computer, or it can be a self containeddevice such as a personal digital assistant (PDA). A wireless terminalcan also be called a system, a subscriber unit, a subscriber station,mobile station, mobile, remote station, access point, remote terminal,access terminal, user terminal, user agent, user device, or userequipment (UE). A wireless terminal can be a subscriber station,wireless device, cellular telephone, PCS telephone, cordless telephone,a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL)station, a personal digital assistant (PDA), a handheld device havingwireless connection capability, or other processing device connected toa wireless modem. A base station (e.g., access point or Node B) canrefer to a device in an access network that communicates over theair-interface, through one or more sectors, with wireless terminals. Thebase station can act as a router between the wireless terminal and therest of the access network, which can include an Internet Protocol (IP)network, by converting received air-interface frames to IP packets. Thebase station also coordinates management of attributes for the airinterface.

Moreover, various functions described herein can be implemented inhardware, software, firmware, or any combination thereof. If implementedin software, the functions can be stored on or transmitted over as oneor more instructions or code on a computer-readable medium.Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage media can be anyavailable media that can be accessed by a computer. By way of example,and not limitation, such computer-readable media can comprise RAM, ROM,EEPROM, CD-ROM or other optical disk storage, magnetic disk storage orother magnetic storage devices, or any other medium that can be used tocarry or store desired program code in the form of instructions or datastructures and that can be accessed by a computer. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and blu-ray disc (BD), where disks usuallyreproduce data magnetically and discs reproduce data optically withlasers. Combinations of the above should also be included within thescope of computer-readable media.

Various techniques described herein can be used for various wirelesscommunication systems, such as Code Division Multiple Access (CDMA)systems, Time Division Multiple Access (TDMA) systems, FrequencyDivision Multiple Access (FDMA) systems, Orthogonal Frequency DivisionMultiple Access (OFDMA) systems, Single Carrier FDMA (SC-FDMA) systems,and other such systems. The terms “system” and “network” are often usedherein interchangeably. A CDMA system can implement a radio technologysuch as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRAincludes Wideband-CDMA (W-CDMA) and other variants of CDMA.Additionally, CDMA2000 covers the IS-2000, IS-95 and IS-856 standards. ATDMA system can implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system can implement a radiotechnology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) is an upcoming release that usesE-UTRA, which employs OFDMA on the downlink and SC-FDMA on the uplink.UTRA, E-UTRA, UMTS, LTE and GSM are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP). Further,CDMA2000 and UMB are described in documents from an organization named“3rd Generation Partnership Project 2” (3GPP2).

Various aspects will be presented in terms of systems that can include anumber of devices, components, modules, and the like. It is to beunderstood and appreciated that the various systems can includeadditional devices, components, modules, etc. and/or omit some or all ofthe devices, components, modules etc. discussed in connection with thefigures. A combination of these approaches can also be used.

Referring now to the drawings, FIG. 1 illustrates a system 100 thatfacilitates operation of mobile relay nodes within a wirelesscommunication system in accordance with various aspects describedherein. As FIG. 1 illustrates, system 100 can include one or morenetwork nodes (also referred to herein as Node Bs or eNBs, cells ornetwork cells, base stations, access points (APs), etc.). Network nodesin system 100 can include, for example, one or more network nodes thatprovide communication service to one or more UEs 140 either indirectlyor directly (not shown), referred to herein as donor eNBs (DeNBs). Forexample, as shown in system 100, DeNBs can include a source eNB 120 anda target eNB 130, as described in further detail below. Additionally,network nodes in system 100 can include one or more relay nodes (RNs)110, which can assist in facilitating communication between respectiveDeNBs and one or more UEs 140. As used herein, a UE can also be referredto as an access terminal (AT), mobile terminal, user or mobile station,etc.

In accordance with one aspect, UE 140 can engage in one or more uplink(UL, also referred to herein as reverse link (RL)) communications withsource eNB 120, target eNB 130, and/or RN 110, and similarly nodes110-130 can engage in one or more downlink (DL, also referred to hereinas forward link (FL)) communications to UE(s) 140. In turn, RN 110 canengage in one or more access communications with UE(s) 140 and/orbackhaul communications with source eNB 120 and/or target eNB 130. Asused herein, “uplink access” refers to communications from UE(s) 140 toRN 110, and “downlink access” refers to communications from RN 110 toUE(s) 140. Similarly, “uplink backhaul” refers to communications from RN110 to source eNB 120 and/or target eNB 130, and “downlink backhaul”refers to communications from source eNB 120 and/or target eNB 130 to RN110. Additionally or alternatively, RN 110, eNBs 120 and/or 130, and/orUE(s) 140 can engage in any suitable communication(s) with each other,with other devices or entities in system 100, and/or any other suitableentities.

In one example, backhaul communication between RN 110 and eNBs 120and/or 130 can be conducted in any suitable manner. For example, abackhaul link from RN 110 to eNBs 120 and/or 130 can be a direct link,an indirect link (e.g., via a central network entity, not shown), and/orany other suitable link(s). Further, communication links between RN 110and some eNBs 120 and/or 130, as well as communication links between RN110 and some UEs 140, can be implemented using any suitable wired orwireless communication technology or combination of technologies. Tothis end, RN 110, eNBs 120 and/or 130, and/or UE(s) 140 can utilizerespective transceivers, network ports or interfaces, and/or any othersuitable means for communication within system 100.

In accordance with one aspect, RN 110 can include some or all of thefunctionality of an eNB in system 100, such as source eNB 120, targeteNB 130, or the like. Alternatively, RN 110 can be a specialized networknode dedicated to assisting in communication between a DeNB and relatedUEs 140. For example, RN 110 can operate to relay information from aDeNB to one or more UEs 140 in a transparent manner to said UEs 140.Thus, in one example, RN 110 can communicate to a UE 140 withoutproviding physical signals to the UE 140 that identify RN 110.Alternatively, RN 110 can operate in a fully or partiallynon-transparent manner to UEs 140. For example, RN 110 can make itspresence known to a UE 140 in order to facilitate channel qualityreporting at the UE 140 corresponding to a channel between the UE 140and RN 110.

In accordance with another aspect, RN 110 can be implemented as astationary relay or a mobile relay. In one example, a stationary relaycan be fixed at a given geographic location and configured to associatewith one or more eNBs within range of its location. Respective eNBs towhich a stationary relay associates can be predefined or otherwiseconstant, or alternatively a stationary relay can associate with varyingeNBs over time based on various criteria. Alternatively, a mobile relaycan be capable of movement between geographic areas. A mobile relay canbe utilized, for example, in the case of a mass transit vehicle (e.g., apassenger train, bus, airplane, etc.) to provide continuouscommunication coverage for the passengers aboard the vehicle as thevehicle moves through respective network cells. As a mobile relay movesfrom the coverage of one eNB to the coverage of another eNB, the relaycan perform a handover operation to associate with the new eNB. Forexample, as shown in system 100, RN 110 can perform a handover operationto discontinue association with source eNB 120 and to establishassociation with target eNB 130. As used herein, a handover operationconducted by a mobile RN 110 is referred to as a “relay handover.”

As a mobile RN 110, depending on implementation, can be capable ofrelatively rapid movement between coverage areas, a mobile RN 110 insome cases can require substantially frequent relay handovers. However,it can be appreciated that relay handovers performed at a relativelyhigh frequency can affect respective UEs 140 that interact with thecorresponding RN 110. For example, in the case of a UE 140 that does notmove with RN 110, the UE 140 can detect and associate with RN 110 uponRN 110 coming into range of UE 140. However, as RN 110 subsequentlymoves out of range of UE 140, UE 140 is required to hand over back to aserving base station. In another example, in the case of a UE 140 thatdoes move with RN 110, the UE 140 can associate with RN 110 andcommunicate with respective eNBs through RN 110 in such a way that ismade substantially transparent to the UE 140. To accomplish this,respective communication channels between RN 110 and a target eNB 130must be established when RN 110 moves from the coverage of a source eNB120 to the coverage of the target eNB 130. However, if establishment ofthe communication channels fails or is significantly delayed (e.g., dueto communication failure, failure of the target eNB 130 to act within asufficient amount of time, etc.), the connection between RN 110 and thenetwork corresponding to eNBs 120 and 130 can be lost, resulting in adegradation or loss of communication service to the UEs 140 associatedwith RN 110.

Accordingly, to mitigate reduced user experience associated withhandover of RN 110 from source eNB 120 to target eNB 130, variousentities in system 100 can implement one or more measures as shown byFIG. 1 to facilitate enhanced support of mobility for RN 110. In a firstexample, RN 110 and/or target eNB 130 can utilize a backhaulconfiguration module 112 to facilitate semi-static assignment of controlchannel resources at target eNB 130 based on hand in or hand out ofmobile relays. In a second example, RN 110 and eNBs 120-130 canimplement radio resource control (RRC) configuration of RN 110 byvarious means. For example, a partitioning adjustment module 114 at RN110, a partitioning indicator module 122 at source eNB 120, and/or aresource partitioning module 132 at target eNB 130 can be utilized toconfigure an access/backhaul resource partitioning arrangement utilizedfor communication between eNBs 120-130 and RN 110. In a third example,RN 110 and/or eNBs 120-130 can utilize a QoS preservation module 116and/or other suitable means to ensure maintenance of QoS requirementsduring a relay handover. Various examples of techniques that can beutilized by RN 110 and eNBs 120-130, as well as the modules utilized bysuch entities as illustrated by FIG. 1, are described in further detailherein.

In accordance with one aspect, a predetermined or configurable amount ofresources can be semi-statically reserved and/or allocated for backhaulcommunication between RN 110 and eNB 120 and/or 130. For example, aRelay Physical Downlink Control Channel (R-PDCCH) can be assigned forcommunication from an eNB 120 or 130 to RN 110. In one example,resources for R-PDCCH can be reserved or allocated in a time-divisionmultiplexed (TDM) and/or frequency-division multiplexed (FDM) manner. Inthe event that RN 110 is a mobile relay, an eNB 120 and/or 130 canpotentially serve multiple RNs 110 due to movement of respective RNs 110into and out of coverage of the eNB 120 and/or 130. Accordingly, in sucha case the reservation and/or allocation of relay control resources at adonor cell corresponding to an eNB 120 and/or 130 can be adjusted basedon the number of RNs 110 served by the cell.

In one example, upon establishment of a connection between RN 110 and atarget eNB 130 (e.g., through a handover, activation of RN 110, etc.)and/or other system changes, resources for R-PDCCH and other suitablechannels can be allocated for communication between RN 110 and target UE130. However, it can be appreciated that if R-PDCCH allocation and/orother control allocation experiences a significant amount of latency,one or more UEs 140 associated with RN 110 can experience partial tocomplete outage. For example, if RN 110 fails to be served upon ahandover and drops connection with target eNB 130, then all UEs 140associated with RN 110 and/or target eNB 130 can consequentially havetheir connections dropped. Accordingly, it can be appreciated that itwould be desirable to establish resources for communication between RN110 and target eNB 130 as fast as possible.

In general, it can be appreciated that broadcast control channel setup,such as that which is performed for handover of a UE, is a substantiallyslow process. For instance, in many cases a UE is required to waitaccording to an associated periodicity before a channel is set up.Further, channel setup can require paging of other served users relatingto a change in system configuration caused by the channel setup. Forexample, if two resource blocks (RBs) are utilized in a FDM fashion in agiven cell for one or more control channels, informing users of a changeto these channels requires paging of substantially all users, which isgenerally a slow process (e.g., on the order of seconds).

Thus, according to one aspect, as broadcast-based control channelreconfiguration is a slow process as noted above, unicast controlchannel setup can be utilized at substantially the same time asconnection setup. This is illustrated in further detail by system 200 inFIG. 2. As system 200 illustrates, a RN 110 and/or other entities insystem 200 can initialize a handover from a source donor cell (e.g.,source eNB 120, not shown in FIG. 2) to a target donor cell (e.g.,target eNB 130). In response to initialization of the handover, abackhaul configuration module 112 and/or other means associated with RN110 can utilize a configuration signaling detector 212 and/or othermeans to receive relay configuration messaging from target eNB 130.Further, RN 110 can utilize a configuration signaling processor 214 orother suitable mechanisms to establish connection with target eNB 130 atleast in part by configuring one or more relay backhaul control channels(e.g., R-PDCCH, etc.) based on the relay configuration messaging. In oneexample, based at least in part on received relay configurationmessaging, configuration signaling processor 214 and/or other suitablemechanisms associated with RN 110 can be utilized to determine an amountof resources to allocate for the one or more relay backhaul controlchannels as a function of a number of associated users.

Correspondingly, target eNB 130 can be configured to detect a requestedinitialization of communication service for RN 110 or another suitablenetwork apparatus in association with a handover of RN 110. Target eNB130 can further include a relay node identifier 222 that can be operableto identify RN 110 as a relay node. In response to identifying RN 110 asa relay node, target eNB 130 can further utilize a backhaulconfiguration generator 232 to configure one or more relay controlchannels (e.g., R-PDCCH, etc.) for use by RN 110 and a configurationsignaling module 234 to establish communication with RN 110 over the oneor more relay backhaul control channels at least in part bycommunicating relay configuration messaging to RN 110.

In the case of broadcast-based R-PDCCH or other control channelconfiguration, it can be appreciated that control information can becarried in the master information block (MIB) or system informationblocks (SIBs). Alternatively, due to the relatively slow speed ofbroadcast-based control configuration as noted above, unicast controlreconfiguration can be performed within system 200 at substantially thesame time as connection setup. Thus, in addition to carrying controlchannel information in the MIB and/or SIBs, control channel informationcan additionally be signaled by configuration signaling module 234and/or other suitable mechanisms in system 200 via unicast signaling,such as unicast layer 3 (L3) messaging or the like.

In another example, configuration signaling module 234 can communicatedynamic layer 1 (L1) signaling to RN 110, e.g., in a similar manner to aPhysical Control Format Indicator Channel (PCFICH). This can be done,for example, in the case of TDM control, FDM control, and/or any othersuitable control type(s). In accordance with one aspect, L1 signaling,L3 signaling, and/or other suitable signaling provided by target eNB 130can be utilized to direct an amount of resources to be associated withone or more relay backhaul control channels. In one example, the amountof resources to be associated with the one or more relay backhaulcontrol channels can be determined as a function of a number of relaynodes served by target eNB 130. In another example, a set of possiblecontrol channel resources (e.g., based on interleaving level, localizedvs. distributed, etc.) can be pre-defined such that an index of eachpossibility can be broadcasted. Thus, for example, target eNB 130 canidentify at least one candidate resource allocation and indicesrespectively associated with the at least one candidate resourceallocation, select a candidate resource allocation to be utilized by RN110 for the one or more relay backhaul control channels and an indexcorresponding to the candidate resource allocation to be utilized by RN110 in order to obtain a selected index, and communicate the selectedindex to RN 110 within relay configuration messaging.

By way of example, an indication can be provided by target eNB 130within a given subframe that informs one or more users that a givennumber of subframes is allocated for control. As described above,similar techniques can be utilized for relay control channels. Forexample, as PDCCH size can be controlled by PCFICH, R-PDCCH size can beindicated by PCFICH. However, in the event that the initial controlsignals in a control transmission are not capable of being received by arelay node, relay control channel configuration can be achieved by usinga fixed allocation of RBs (e.g., 1 RB) that indicates how manyadditional RBs are utilized for relay control. In one example, theamount of additional relay control RBs can vary from subframe tosubframe. Thus, for example, in the event that the amount of resourcesto be associated with one or more relay backhaul control channels by RN110 corresponds to one or more RBs, target eNB 130 can embed, on apredefined backhaul RB in the relay configuration messaging, a number ofadditional RBs to be associated with the one or more relay backhaulcontrol channels.

According to another aspect, at RN 110, configuration signalingprocessor 214 and/or other suitable means can be utilized to configure aresource allocation for one or more relay backhaul control channelsbased on relay configuration messaging as generated and transmitted asdescribed above. For example, if the relay configuration messagingincludes index information, RN 110 can obtain information relating to aset of candidate resource allocations for one or more relay backhaulcontrol channels and indices respectively associated with candidateresource allocations in the set. RN 110 can then identify an indexprovided within the index information and configure a resourceallocation for the one or more relay backhaul control channels accordingto a candidate resource allocation that corresponds to the indexprovided within the index information. Further, if the resourceallocation for one or more relay backhaul control channels correspondsto an amount of RBs, RN 110 can be configured to receive relayconfiguration messaging on a designated RB, identify an indicated numberof additional RBs within the relay configuration messaging, and allocatethe indicated number of additional RBs for use by the one or more relaybackhaul control channels.

According to a further aspect, information corresponding to anallocation of resources for R-PDCCH and/or other relay backhaul controlchannels can be updated subsequent to initialization of a connectionbetween RN 110 and target eNB 130. For example, target eNB 130 can beconfigured to identify an updated resource allocation to be utilized byRN 110 for one or more relay backhaul control channels and tocommunicate updated relay configuration messaging to RN 110 thatindicates the updated resource allocation. RN 110 can subsequentlyreceive the updated relay configuration messaging from target eNB 130and update configuration of the one or more relay backhaul controlchannels based on the updated relay configuration messaging.

In accordance with an additional aspect, if there are no relay resourcesin a target cell (e.g., corresponding to a target eNB 130), a mobile RN110 can bootstrap from a typical UE setup procedure to establish aconnection with target eNB 130 and subsequently set up R-PDCCH and/orother suitable control channels. For example, as shown by system 300 inFIG. 3, handover of RN 110 can be initially conducted as if RN 110 is aUE. Subsequently during the handover process, an identificationsignaling module 312 and/or other suitable means associated with RN 110can indicate to target eNB 130 that RN 110 is a relay node. Based onthis indication, an identification signaling detector 322 and/or othersuitable means at target eNB 130 can identify RN 110 as a relay node,such that setup of relay control channels can be initialized.

Thus, in one example, RN 110 can initialize a mobile device handover,wherein RN 110 can establish identity as a relay node with target eNB130 and receive relay configuration messaging from target eNB 130 inresponse to establishing identity as a relay node with target eNB 130.Correspondingly, target eNB 130 can initialize a mobile device handoverfor RN 110 in response to requested initialization of communicationservice for RN 110. Subsequently, target eNB 130 can identify RN 110 asa relay node based at least in part on signaling received from RN 110 inconnection with the mobile device handover.

While various examples and aspects described above relate to thespecific case of R-PDCCH setup, it should be appreciated that othercontrol channels can be configured via similar techniques. For example,a Physical Random Access Channel (PRACH) can be configured for backhaulcommunication between RN 110 and target eNB 130 using similar techniquesas those described above. In addition, it should be appreciated that anyother suitable control channel(s) can be configured using the techniquesdescribed above. Moreover, unless explicitly stated otherwise, theclaimed subject matter is not intended to be limited to any specificcontrol channel(s).

According to another aspect, when a mobile relay hands over from one eNBto another, the access/backhaul partitioning of the relay may in somecases require modification. For example, it can be appreciated thatrelay backhaul and access can be partitioned in time, such that somesubframes are allocated for eNB to relay (backhaul) communication andother subframes are allocated for relay to UE (access) communication. Inthe case that each relay can have a different access to backhaulconfiguration, when a relay moves from one eNB to another eNB, the neweNB can potentially have a different access to backhaul configuration asthe previous eNB. Further, UEs associated with a relay node can beconfigured to expect to communicate with the relay node on accesssubframes in a given cell. However, upon movement to a new cell, thepartitioning of access and backhaul subframes can change. As such achange is not immediately relayed to UEs associated with the relay node,it would be desirable to implement various techniques for synchronizingall entities involved in communication with the relay node with respectto access/backhaul resource partitioning.

Thus, to facilitate a relay handover without substantial serviceinterruption to relay UEs, various techniques are provided herein. In afirst example illustrated by system 400 in FIG. 4, a source eNB 120relating to a relay handover can inform the target eNB 130 ordestination eNB relating to the relay handover of the partitioninginformation of the relay node (not shown in FIG. 4). For example, asillustrated by system 400, a source eNB 120 can obtain informationrelating to an access/backhaul resource partitioning corresponding to anassociated relay node, after which source eNB 120 can utilize a handoverpreparation module 412 and/or other suitable mechanisms to directrequested handover of the associated relay node to target eNB 130.Further, in connection with the requested handover, a partitioningindicator module 122 and/or other suitable means can be used by sourceeNB 120 to indicate the access/backhaul resource partitioning to targeteNB 130. In one example, the access/backhaul partitioning can beindicated to target eNB 130 by partitioning indicator module 122 priorto the requested handover. Further, by indicating the access/backhaulpartitioning to target eNB 130, it can be appreciated that source eNB120 can direct a partitioning of access subframes and backhaulsubframes, and/or other access/backhaul resource partitioning, asestablished by target eNB 130 for an associated relay node.

Further, at target eNB 130, upon detecting requested handover of a relaynode from source eNB 120 via a handover preparation module 412 and/orother suitable means, target eNB 130 can utilize a backhaulconfiguration module 112 or other mechanisms to receive information fromsource eNB 120 in connection with the requested handover relating to anaccess/backhaul resource partitioning utilized by source eNB 120 for therelay node. Based on the information received from source eNB 120, aresource partitioning module 132 at target eNB 130 can configure anallocation of access subframes and backhaul subframes corresponding tothe relay node. In one example, information relating to theaccess/backhaul resource partitioning for the relay node can be receivedfrom source eNB 120 prior to the requested handover.

In accordance with one aspect, resource partitioning module 132 attarget eNB 130 can utilize information received from source eNB 120 inorder to configure an allocation of access subframes and backhaulsubframes corresponding to a relay node that substantially preserves theaccess/backhaul resource partitioning utilized by source eNB 120 for therelay node. In turn, target eNB 130 can inform the relay node of theresource partitioning if necessary to facilitate substantially seamlessoperation through the handover.

In one example, an assigned Random Access Channel (RACH) occasion bytarget eNB 130 can be a current UL backhaul subframe for the relay. Byconfiguring an allocation of access subframes and backhaul subframescorresponding to a relay node such that an assigned RACH occasionassociated with the relay node occurs on an UL backhaul subframecorresponding to the relay node, a relay node can be prevented frombeing required to transmit on its access subframes, which in some casesmay be substantially impracticable or impossible due to relay nodecapabilities.

In another example, an allocation of access subframes and backhaulsubframes corresponding to a relay node can be configured by target eNB130 such that a Random Access Response (RAR) transmitted by target eNB130 to the relay node occurs on a DL backhaul subframe for the relaynode. This can be done, for example, to enable reception of the RAR atthe relay node according to the configured backhaul resources of therelay node.

In a third example, resource partitioning module 132 can be operable toconfigure an allocation of access subframes and backhaul subframescorresponding to a relay node such that respective non-removable accesssubframes corresponding to the relay node are allocated as accesssubframes. As used herein, non-removable access subframes are defined assubframes that cannot be utilized by a relay node as backhaul due tovarious constraints. By way of specific, non-limiting example, in aten-subframe radio frame, non-removable access subframes can includesubframes 0, 4, 5, and 9 for FDD and 0, 1, 5, and 6 for TDD. An exampleof non-removable access subframes for FDD is illustrated by diagram 500in FIG. 5. In one example, non-removable access subframes can presentdue to Multimedia Broadcast over Single-Frequency Network (MBSFN)constraints and/or other constraints. For example, in the event that arelay node configures backhaul subframes as MBSFN subframes,non-removable access subframes can be defined as the subframes whichcannot be configured as MBSFN subframes by the relay node.

In another example, as further illustrated by diagram 500, non-MBSFNsubframes can be identified from the perspective of a relay node asopposed to a donor eNB. Thus, if an offset exists between the subframesof an eNB and the subframes of an associated relay node, the eNB can beconfigured to identify non-MBSFN subframes based on the configuration ofthe relay node. For example, as shown in diagram 500, in the event of atwo-subframe offset exists between an eNB and a relay node, the eNB canidentify non-MBSFN subframes according to a beginning subframe index of2 instead of 0. Accordingly, referring back to system 400, resourcepartitioning module 132 and/or other means associated with target eNB130 can be operable to identify a subframe offset corresponding to arelay node, to obtain information relating to one or more predeterminednon-MBSFN subframe positions within a given radio frame, and todetermine the non-MBSFN subframe positions within the given radio framewith respect to the relay node based on the subframe offsetcorresponding to the relay node.

According to an alternative aspect, the relay node can switch itssubframes and/or other resources from access to backhaul or vice versain response to information obtained from a destination eNB (e.g., a RACHallocation of the destination eNB, etc.) in order to facilitate itselffor handover. This is illustrated by system 600 in FIG. 6. Asillustrated by system 600, a RN 110 can utilize a backhaul configurationmodule or other mechanisms to identify an allocation of access subframesand backhaul subframes associated with backhaul communication.Subsequently, upon initializing a handover from a source eNB to targeteNB 130, a channel allocation analyzer 612 and/or other means can beutilized by RN 110 to obtain information relating to an access/backhaulsubframe allocation utilized by target eNB 130. Based on theaccess/backhaul subframe allocation utilized by target eNB 130, apartitioning adjustment module 114 or other mechanisms at RN 110 canadjust one or more subframes in the allocation of access subframes andbackhaul subframes.

In one example, adjustment of subframes in an allocation of accesssubframes and backhaul subframes utilized by RN 110 can occur prior to arequested handover. Further, RN 110 can adjust one or more subframes inits access/backhaul allocation in response to a RACH allocation utilizedby target eNB 130. For example, RN 110 can adjust allocation ofrespective subframes such that a RACH occasion assigned by target eNB130 occurs on an UL backhaul subframe with target eNB 130. Additionallyor alternatively, RN 110 can adjust allocation of respective subframessuch that a RAR transmitted by target eNB 130 occurs on a DL backhaulsubframe with target eNB 130.

According to an aspect, RN 110 can utilize partitioning adjustmentmodule 114 to adjust one or more subframes in an allocation of accesssubframes and backhaul subframes in order to facilitate substantialconformance with an access/backhaul subframe allocation utilized bytarget eNB 130. For example, if a subframe allocated as access by RN 110is allocated for backhaul at target eNB 130, partitioning adjustmentmodule 114 can facilitate switching the subframe from access to backhaulat RN 110. In one example, RN 110 can indicate a result of suchadjusting to one or more UEs (not shown in system 600) served by RN 110,thereby enabling the UE(s) to adjust their communication schedule withRN 110 such that no communication from the UE(s) to RN 110 is conductedon the backhaul subframes of RN 110.

In an additional example, partitioning adjustment as performed by RN 110in system 600 can take non-MBSFN subframes and/or other non-removableaccess subframes into consideration in a similar manner to thatdescribed with respect to system 400. Thus, partitioning adjustmentmodule 114 can be operable to adjust one or more subframes in anallocation of access subframes and backhaul subframes such thatrespective non-MBSFN subframes are allocated as access subframes.

While systems 400 and 600 and their corresponding description describevarious techniques by which access and backhaul resources can bepartitioned for a relay node, it should be appreciated that othertechniques could be utilized and that, unless explicitly statedotherwise, the claimed subject matter is not intended to be limited toany specific technique(s). Further, it should be appreciated that thetechniques described herein could be combined with each other and/orother suitable techniques in any suitable manner.

In accordance with yet another aspect, it can be appreciated that relayhandover can in some cases require higher reliability and quality ofservice (QoS) due to the fact that the relay can potentially serve alarge number of UEs. For example, as described above, if a radio linkfailure and/or other failure occurs during a relay handover,substantially all relay UEs could in some cases lose their backhaulconnection for a prolonged period of time. Accordingly, it would bedesirable to implement techniques by which QoS can be preserved inassociation with a relay handover. Various measures that can beimplemented to the furtherance of these and related ends are illustratedby system 700 in FIG. 7.

In one example, RN 110 can be equipped with a QoS preservation module116 or other suitable means to ensure that QoS requirements associatedwith a relay handover to target eNB 130 are maintained. For example,upon initializing a relay handover to target eNB 130, QoS preservationmodule 116 can identify a QoS requirement for the relay handover anddirect communication in connection with the relay handover such that theQoS requirement for the relay handover is substantially preserved.Correspondingly, target eNB 130 can additionally or alternativelyutilize a QoS preservation module 116 and/or other suitable means tomaintain QoS targets for a relay handover. For example, target eNB 130can be operable to detect a requested initialization of communicationservice for RN 110 in association with a handover of RN 110, based onwhich QoS preservation module 116 can identify a QoS requirement for thehandover of RN 110 and direct communication in connection with thehandover of RN 110 such that the QoS requirement for the handover of RN110 is substantially preserved.

In accordance with one aspect, QoS preservation modules 116 at RN 110and/or target eNB 130 can direct communication of random accesssignaling associated with a handover of RN 110, such as PRACH signalingor the like, such that the QoS requirement for the handover issubstantially preserved. By way of non-limiting example, this can beachieved by improving the detectability of PRACH and/or reducing thenumber of PRACH attempts. In a first example, a random access preambleconfiguration can be chosen such that longer preamble sequences can beused to increase preamble energy. Thus, for example, a QoS preservationmodule 116 associated with RN 110 and/or target eNB 130 can beassociated with a random access preamble selector 712 or the like inorder to increase length of respective preamble sequences associatedwith random access signaling.

In a second example, initial PRACH transmission power can be increasedin order to reduce PRACH attempts. Thus, for example, RN 110 can utilizea random access power control module 714 and/or other suitablemechanisms to increase transmission power for initial random accesssignaling performed in connection with the relay handover. In a furtherexample, power can be increased for initial random access signalingbased on a predefined relay power offset and/or any other suitable poweroffset associated with RN 110.

In a third example, target eNB 130 can be configured to avoid schedulingany transmissions in the relay random access region in order to avoidcollisions with random access signaling transmitted by RN 110. Thus, forexample, a transmission scheduler 732 and/or other mechanisms associatedwith target eNB 130 can be operable to identify a random access regionassociated RN 110 in connection with a handover of RN 110 and abstainfrom scheduling transmissions on the random access region associatedwith RN 110. Additionally, target eNB 130 can schedule re-transmissionsthat would interfere with relay PRACH using adaptive Hybrid AutomaticRepeat Request (HARQ) such that the re-transmissions can be scheduled ondifferent resources. Put another way, transmission scheduler 732 canconfigure respective re-transmissions such that respectivere-transmissions identified as potentially conflicting with the randomaccess region associated with RN 110 in connection with the handover ofRN 110 are adaptively scheduled on resources disparate from resourcescorresponding to the random access region associated with RN 110.

In a fourth example, RARs can be configured to be sent within system 700with minimum delay. Thus, for example, RN 110 can have a decreased timewindow compared to regular UEs corresponding to a maximum acceptabletime interval at which a RAR can be received from target eNB 130following random access signaling performed in connection with a relayhandover. Correspondingly, target eNB 130 can be configured with adecreased time interval with which a RAR is transmitted to RN 110 inresponse to random access signaling provided by RN 110 in connectionwith a handover of RN 110. In one example, if a RAR does not arrive atRN 110 within the acceptable time window, RN 110 can directre-transmission of the random access signaling, and/or the accessattempt can be otherwise repeated. Accordingly, by utilizing reducedtime intervals for a random access procedure relating to a relayhandover in this manner, it can be appreciated that the relay handovercan be restarted substantially quickly (e.g., on the order ofmilliseconds) upon failure of the random access procedure as compared tothat for a standard UE.

According to one aspect, one or more of the techniques provided above toensure QoS targets associated with a relay handover can be adjustablebased on a number of users associated with RN 110. Thus, for example, ifRN 110 is associated with no or substantially few users, handover of RN110 can be conducted in a similar manner to handover of a UE. In anotherexample, the number and/or extent of techniques utilized for a relayhandover of RN 110 can be scalable based on the number of users servedby RN 110.

According to another aspect, RN 110 can have more than one candidatetarget eNB when handing over. This set of candidate target eNBs can bemanaged by RN 110, a serving eNB for RN 110, and/or any other suitableentity. Accordingly, if the initial handover attempt fails, the servingeNB for RN 110 can instruct the relay to hand over to an alternativecandidate eNB. In another example, RN 110 can identify a plurality ofcandidate target donor eNBs, such as those corresponding to a candidatetarget eNB list 722. Subsequently, in response to detecting failure of arelay handover to a target donor eNB, a target eNB selector 716 or othermeans can initialize an alternative relay handover to a candidate targetdonor eNB selected from the plurality of candidate target donor eNBs.

Referring now to FIGS. 8-14, methodologies that can be performed inaccordance with various aspects set forth herein are illustrated. While,for purposes of simplicity of explanation, the methodologies are shownand described as a series of acts, it is to be understood andappreciated that the methodologies are not limited by the order of acts,as some acts can, in accordance with one or more aspects, occur indifferent orders and/or concurrently with other acts from that shown anddescribed herein. For example, those skilled in the art will understandand appreciate that a methodology could alternatively be represented asa series of interrelated states or events, such as in a state diagram.Moreover, not all illustrated acts may be required to implement amethodology in accordance with one or more aspects.

With reference to FIG. 8, illustrated is a first method 800 for managingmobility of a relay node within a wireless communication environment. Itis to be appreciated that method 800 can be performed by, for example, arelay node (e.g., RN 110) and/or any other appropriate network entity.Method 800 begins at block 802, wherein a handover from a source donorcell (e.g., source eNB 120) to a target donor cell (e.g., target eNB130) is initialized. At block 804, relay configuration messaging isreceived from the target donor cell in response to initialization of thehandover. At block 806, a connection with the target donor cell isestablished at least in part by configuring one or more relay backhaulcontrol channels based on the relay configuration messaging.

Turning now to FIG. 9, a flow diagram of a second method 900 formanaging mobility of a relay node within a wireless communicationenvironment is illustrated. Method 900 can be performed by, for example,a target donor cell of a relay handover (e.g., target eNB 130) and/orany other appropriate network entity. Method 900 begins at block 902,wherein a requested initialization of communication service for anetwork apparatus (e.g., RN 110) is detected in association with ahandover of the network apparatus. At block 904, the network apparatusis identified as a relay node. At block 906, communication with thenetwork apparatus is established over one or more relay backhaul controlchannels at least in part by communicating relay configuration messagingto the network apparatus in response to identifying the networkapparatus as a relay node.

FIG. 10 illustrates a third method 1000 for managing mobility of a relaynode within a wireless communication environment. Method 1000 can beperformed by, for example, a source donor cell of a relay handover(e.g., source eNB 120) and/or any other suitable network entity. Method1000 begins at block 1002, wherein information is obtained relating toan access/backhaul resource partitioning corresponding to an associatedrelay node. At block 1004, a requested handover of the associated relaynode to a target cell is detected. At block 1006, the access/backhaulresource partitioning is indicated to the target cell in connection withthe requested handover.

With reference next to FIG. 11, illustrated is a fourth method 1100 formanaging mobility of a relay node within a wireless communicationenvironment. Method 1100 can be performed by, for example, a destinationcell of a relay handover and/or any other appropriate network entity.Method 1100 begins at block 1102, wherein requested handover of a relaynode from a source cell is detected. At block 1104, information isreceived from the source cell in connection with the requested handoverrelating to an access/backhaul resource partitioning utilized by thesource cell for the relay node. At block 1106, an allocation of accesssubframes and backhaul subframes corresponding to the relay node isconfigured based at least in part on the information received from thesource cell.

Turning to FIG. 12, a flow diagram of a fifth method 1200 for managingmobility of a relay node within a wireless communication environment isillustrated. Method 1200 can be performed by, for example, a relay nodeand/or any other appropriate network entity. Method 1200 begins at block1202, wherein an allocation of access subframes and backhaul subframesassociated with relay communication is identified. At block 1204, ahandover from a source eNB to a destination eNB is initialized. At block1206, information is obtained relating to an access/backhaul subframeallocation utilized by the destination eNB. At block 1208, one or moresubframes in the allocation of access subframes and backhaul subframesare adjusted based on the access/backhaul subframe allocation utilizedby the destination eNB.

FIG. 13 illustrates a sixth method 1300 for managing mobility of a relaynode within a wireless communication environment. Method 1300 can beperformed by, for example, a donor cell involved in a relay handoverand/or any other suitable network entity. Method 1300 begins at block1302, wherein a requested initialization of communication service for arelay node in association with a handover of the relay node is detected.At block 1304, a QoS requirement for the handover of the relay node isidentified. At block 1306, communication in connection with the handoverof the relay node is directed such that the QoS requirement for thehandover of the relay node is substantially preserved.

FIG. 14 illustrates a seventh method 1400 for managing mobility of arelay node within a wireless communication environment. Method 1400 canbe performed by, for example, a relay node and/or any other suitablenetwork entity. Method 1400 begins at block 1402, wherein a relayhandover to a target donor eNB is initialized. At block 1404, a QoSrequirement for the relay handover is identified. At block 1406,communication in connection with the relay handover is directed suchthat the QoS requirement for the relay handover is substantiallypreserved.

Referring next to FIGS. 15-21, respective apparatuses 1500-2100 that canbe utilized in connection with various aspects herein are illustrated.It is to be appreciated that apparatuses 1500-2100 are represented asincluding functional blocks, which can be functional blocks thatrepresent functions implemented by a processor, software, or combinationthereof (e.g., firmware).

Turning first to FIG. 15, a first apparatus 1500 that facilitatescoordination of a relay node handover within a wireless communicationsystem is illustrated. Apparatus 1500 can be implemented by a relay node(e.g., RN 110) and/or any other suitable network entity and can includea module 1502 for obtaining configuration messaging from a donor eNBrelating to a handover to the donor eNB and a module 1504 forinitializing one or more relay backhaul control channels forcommunication with the donor eNB based at least in part on theconfiguration messaging.

FIG. 16 illustrates a second apparatus 1600 that facilitatescoordination of a relay node handover within a wireless communicationsystem. Apparatus 1600 can be implemented by a target donor cell of arelay handover (e.g., target eNB 130) and/or any other suitable networkentity and can include a module 1602 for identifying a requestedinitialization of communication service for a network device relating toa handover of the network device, a module 1604 for identifying thenetwork device as a relay node, and a module 1606 for establishing oneor more relay backhaul control channels for communication with thenetwork device in response to identifying the network device as a relaynode.

Referring next to FIG. 17, a third apparatus 1700 that facilitatescoordination of a relay node handover within a wireless communicationsystem is illustrated. Apparatus 1700 can be implemented by a sourcedonor cell of a relay handover (e.g., source eNB 120) and/or any othersuitable network entity and can include a module 1702 for identifyingaccess resources and backhaul resources corresponding to a relay nodeand a module 1704 for indicating identities of the access resources andthe backhaul resources to a target cell corresponding to a requestedhandover of the relay node.

Turning now to FIG. 18, a fourth apparatus 1800 that facilitatescoordination of a relay node handover within a wireless communicationsystem is illustrated. Apparatus 1800 can be implemented by a target eNBinvolved in a relay handover and/or any other suitable network entityand can include a module 1802 for receiving information from a sourceeNB in response to a requested handover of a relay node from the sourceeNB relating to a partitioning of access resources and backhaulresources utilized by the source eNB for the relay node and a module1804 for allocating access resources and backhaul resources for therelay node based at least in part on the information received from thesource eNB.

FIG. 19 illustrates a fifth apparatus 1900 that facilitates coordinationof a relay node handover within a wireless communication system.Apparatus 1900 can be implemented by a relay and/or any other suitablenetwork entity and can include a module 1902 for identifying anallocation of access resources and backhaul resources associated withrelay communication, a module 1904 for initializing a relay handover toa target cell, and a module 1906 for adjusting at least a portion of theallocation of access resources and backhaul resources based on anaccess/backhaul resource partitioning associated with the target cell.

Referring to FIG. 20, a sixth apparatus 2000 that facilitatescoordination of a relay node handover within a wireless communicationsystem is illustrated. Apparatus 2000 can be implemented by a donor eNBconducting a relay handover and/or any other suitable network entity andcan include a module 2002 for detecting initialization of a handover ofa relay node and a QoS requirement associated with the handover of therelay node and a module 2004 for managing communication relating to thehandover of the relay node such that the QoS requirement associated withthe handover of the relay node is substantially met.

FIG. 21 illustrates a seventh apparatus 2100 that facilitatescoordination of a relay node handover within a wireless communicationsystem. Apparatus 2100 can be implemented by a relay node and/or anyother suitable network entity and can include a module 2102 foridentifying a target cell for a relay handover and a QoS requirementassociated with the relay handover and a module 2104 for managingcommunication relating to the relay handover such that the QoSrequirement associated with the relay handover is substantially met.

Referring now to FIG. 22, an illustration of a wireless multiple-accesscommunication system is provided in accordance with various aspects. Inone example, an access point 2200 (AP) includes multiple antenna groups.As illustrated in FIG. 22, one antenna group can include antennas 2204and 2206, another can include antennas 2208 and 2210, and another caninclude antennas 2212 and 2214. While only two antennas are shown inFIG. 22 for each antenna group, it should be appreciated that more orfewer antennas may be utilized for each antenna group. In anotherexample, an access terminal 2216 can be in communication with antennas2212 and 2214, where antennas 2212 and 2214 transmit information toaccess terminal 2216 over forward link 2220 and receive information fromaccess terminal 2216 over reverse link 2218. Additionally and/oralternatively, access terminal 2222 can be in communication withantennas 2206 and 2208, where antennas 2206 and 2208 transmitinformation to access terminal 2222 over forward link 2226 and receiveinformation from access terminal 2222 over reverse link 2224. In afrequency division duplex system, communication links 2218, 2220, 2224and 2226 can use different frequency for communication. For example,forward link 2220 may use a different frequency then that used byreverse link 2218.

Each group of antennas and/or the area in which they are designed tocommunicate can be referred to as a sector of the access point. Inaccordance with one aspect, antenna groups can be designed tocommunicate to access terminals in a sector of areas covered by accesspoint 2200. In communication over forward links 2220 and 2226, thetransmitting antennas of access point 2200 can utilize beamforming inorder to improve the signal-to-noise ratio of forward links for thedifferent access terminals 2216 and 2222. Also, an access point usingbeamforming to transmit to access terminals scattered randomly throughits coverage causes less interference to access terminals in neighboringcells than an access point transmitting through a single antenna to allits access terminals.

An access point, e.g., access point 2200, can be a fixed station usedfor communicating with terminals and can also be referred to as a basestation, an eNB, an access network, and/or other suitable terminology.In addition, an access terminal, e.g., an access terminal 2216 or 2222,can also be referred to as a mobile terminal, user equipment, a wirelesscommunication device, a terminal, a wireless terminal, and/or otherappropriate terminology.

Referring now to FIG. 23, a block diagram illustrating an examplewireless communication system 2300 in which various aspects describedherein can function is provided. In one example, system 2300 is amultiple-input multiple-output (MIMO) system that includes a transmittersystem 2310 and a receiver system 2350. It should be appreciated,however, that transmitter system 2310 and/or receiver system 2350 couldalso be applied to a multi-input single-output system wherein, forexample, multiple transmit antennas (e.g., on a base station), cantransmit one or more symbol streams to a single antenna device (e.g., amobile station). Additionally, it should be appreciated that aspects oftransmitter system 2310 and/or receiver system 2350 described hereincould be utilized in connection with a single output to single inputantenna system.

In accordance with one aspect, traffic data for a number of data streamsare provided at transmitter system 2310 from a data source 2312 to atransmit (TX) data processor 2323. In one example, each data stream canthen be transmitted via a respective transmit antenna 2324.Additionally, TX data processor 2314 can format, encode, and interleavetraffic data for each data stream based on a particular coding schemeselected for each respective data stream in order to provide coded data.In one example, the coded data for each data stream can then bemultiplexed with pilot data using OFDM techniques. The pilot data canbe, for example, a known data pattern that is processed in a knownmanner. Further, the pilot data can be used at receiver system 2350 toestimate channel response. Back at transmitter system 2310, themultiplexed pilot and coded data for each data stream can be modulated(e.g., symbol mapped) based on a particular modulation scheme (e.g.,BPSK, QSPK, M-PSK, or M-QAM) selected for each respective data stream inorder to provide modulation symbols. In one example, data rate, coding,and modulation for each data stream can be determined by instructionsperformed on and/or provided by processor 2330.

Next, modulation symbols for all data streams can be provided to a TXMIMO processor 2320, which can further process the modulation symbols(e.g., for OFDM). TX MIMO processor 2320 can then provides N_(T)modulation symbol streams to N_(T) transceivers 2322 a through 2322 t.In one example, each transceiver 2322 can receive and process arespective symbol stream to provide one or more analog signals. Eachtransceiver 2322 can then further condition (e.g., amplify, filter, andupconvert) the analog signals to provide a modulated signal suitable fortransmission over a MIMO channel. Accordingly, N_(T) modulated signalsfrom transceivers 2322 a through 2322 t can then be transmitted fromN_(T) antennas 2324 a through 2324 t, respectively.

In accordance with another aspect, the transmitted modulated signals canbe received at receiver system 2350 by N_(R) antennas 2352 a through2352 r. The received signal from each antenna 2352 can then be providedto respective transceivers 2354. In one example, each transceiver 2354can condition (e.g., filter, amplify, and downconvert) a respectivereceived signal, digitize the conditioned signal to provide samples, andthen processes the samples to provide a corresponding “received” symbolstream. An RX MIMO/data processor 2360 can then receive and process theN_(R) received symbol streams from N_(R) transceivers 2354 based on aparticular receiver processing technique to provide N_(T) “detected”symbol streams. In one example, each detected symbol stream can includesymbols that are estimates of the modulation symbols transmitted for thecorresponding data stream. RX processor 2360 can then process eachsymbol stream at least in part by demodulating, deinterleaving, anddecoding each detected symbol stream to recover traffic data for acorresponding data stream. Thus, the processing by RX processor 2360 canbe complementary to that performed by TX MIMO processor 2320 and TX dataprocessor 2314 at transmitter system 2310. RX processor 2360 canadditionally provide processed symbol streams to a data sink 2364.

In accordance with one aspect, the channel response estimate generatedby RX processor 2360 can be used to perform space/time processing at thereceiver, adjust power levels, change modulation rates or schemes,and/or other appropriate actions. Additionally, RX processor 2360 canfurther estimate channel characteristics such as, for example,signal-to-noise-and-interference ratios (SNRs) of the detected symbolstreams. RX processor 2360 can then provide estimated channelcharacteristics to a processor 2370. In one example, RX processor 2360and/or processor 2370 can further derive an estimate of the “operating”SNR for the system. Processor 2370 can then provide channel stateinformation (CSI), which can comprise information regarding thecommunication link and/or the received data stream. This information caninclude, for example, the operating SNR. The CSI can then be processedby a TX data processor 2318, modulated by a modulator 2380, conditionedby transceivers 2354 a through 2354 r, and transmitted back totransmitter system 2310. In addition, a data source 2316 at receiversystem 2350 can provide additional data to be processed by TX dataprocessor 2318.

Back at transmitter system 2310, the modulated signals from receiversystem 2350 can then be received by antennas 2324, conditioned bytransceivers 2322, demodulated by a demodulator 2340, and processed by aRX data processor 2342 to recover the CSI reported by receiver system2350. In one example, the reported CSI can then be provided to processor2330 and used to determine data rates as well as coding and modulationschemes to be used for one or more data streams. The determined codingand modulation schemes can then be provided to transceivers 2322 forquantization and/or use in later transmissions to receiver system 2350.Additionally and/or alternatively, the reported CSI can be used byprocessor 2330 to generate various controls for TX data processor 2314and TX MIMO processor 2320. In another example, CSI and/or otherinformation processed by RX data processor 2342 can be provided to adata sink 2344.

In one example, processor 2330 at transmitter system 2310 and processor2370 at receiver system 2350 direct operation at their respectivesystems. Additionally, memory 2332 at transmitter system 2310 and memory2372 at receiver system 2350 can provide storage for program codes anddata used by processors 2330 and 2370, respectively. Further, atreceiver system 2350, various processing techniques can be used toprocess the N_(R) received signals to detect the N_(T) transmittedsymbol streams. These receiver processing techniques can include spatialand space-time receiver processing techniques, which can also bereferred to as equalization techniques, and/or “successivenulling/equalization and interference cancellation” receiver processingtechniques, which can also be referred to as “successive interferencecancellation” or “successive cancellation” receiver processingtechniques.

It is to be understood that the aspects described herein can beimplemented by hardware, software, firmware, middleware, microcode, orany combination thereof. When the systems and/or methods are implementedin software, firmware, middleware or microcode, program code or codesegments, they can be stored in a machine-readable medium, such as astorage component. A code segment can represent a procedure, a function,a subprogram, a program, a routine, a subroutine, a module, a softwarepackage, a class, or any combination of instructions, data structures,or program statements. A code segment can be coupled to another codesegment or a hardware circuit by passing and/or receiving information,data, arguments, parameters, or memory contents. Information, arguments,parameters, data, etc. can be passed, forwarded, or transmitted usingany suitable means including memory sharing, message passing, tokenpassing, network transmission, etc.

For a software implementation, the techniques described herein can beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. The software codes can be storedin memory units and executed by processors. The memory unit can beimplemented within the processor or external to the processor, in whichcase it can be communicatively coupled to the processor via variousmeans as is known in the art.

What has been described above includes examples of one or more aspects.It is, of course, not possible to describe every conceivable combinationof components or methodologies for purposes of describing theaforementioned aspects, but one of ordinary skill in the art canrecognize that many further combinations and permutations of variousaspects are possible. Accordingly, the described aspects are intended toembrace all such alterations, modifications and variations that fallwithin the spirit and scope of the appended claims. Furthermore, to theextent that the term “includes” is used in either the detaileddescription or the claims, such term is intended to be inclusive in amanner similar to the term “comprising” as “comprising” is interpretedwhen employed as a transitional word in a claim. Furthermore, the term“or” as used in either the detailed description or the claims is meantto be a “non-exclusive or.”

What is claimed is:
 1. A method performed by a target cell, comprising:detecting a requested handover of a relay node from a source cell to thetarget cell; receiving information from the source cell in connectionwith the requested handover, relating to an access/backhaul resourcepartitioning utilized by the source cell for the relay node; andconfiguring an allocation of access subframes and backhaul subframescorresponding to the relay node, based at least in part on theinformation received from the source cell, such that a random accessresponse (RAR) transmitted to the relay node occurs on a downlinkbackhaul subframe corresponding to the relay node.
 2. The method ofclaim 1, wherein the receiving comprises receiving the information fromthe source cell prior to the requested handover.
 3. The method of claim1, wherein the configuring comprises configuring an allocation of accesssubframes and backhaul subframes corresponding to the relay node thatsubstantially preserves the access/backhaul resource partitioningutilized by the source cell for the relay node.
 4. The method of claim1, wherein the configuring comprises configuring an allocation of accesssubframes and backhaul subframes corresponding to the relay node suchthat an assigned random access channel (RACH) occasion associated withthe relay node occurs on an uplink backhaul subframe corresponding tothe relay node.
 5. The method of claim 1, wherein the configuringcomprises configuring an allocation of access subframes and backhaulsubframes corresponding to the relay node such that respectivenon-Multimedia Broadcast over Single-Frequency Network (MBSFN) subframescorresponding to the relay node are allocated as access subframes. 6.The method of claim 5, wherein the configuring further comprises:identifying a subframe offset corresponding to the relay node; obtaininginformation relating to one or more predetermined non-MBSFN subframepositions within a given radio frame; and determining the one or morepredetermined non-MBSFN subframe positions within the given radio framewith respect to the relay node based on the subframe offsetcorresponding to the relay node.
 7. The method of claim 1, furthercomprising transmitting information to the relay node that indicates theallocation of access subframes and backhaul subframes corresponding tothe relay node.
 8. The method of claim 7, wherein the transmittingcomprises transmitting the information to the relay node during therequested handover of the relay node or after the requested handover ofthe relay node.
 9. The method of claim 7, wherein the transmittingcomprises transmitting the information to the relay node using unicastlayer 3 (L3) signaling.
 10. A target cell, comprising: a memory thatstores data relating to a relay node, a source cell, and a requestedhandover of the relay node from the source cell to the target cell; anda processor configured to receive information, from the source cell inconnection with the requested handover, relating to an access/backhaulresource partitioning utilized by the source cell for the relay node,and to determine an allocation of access subframes and backhaulsubframes corresponding to the relay node, based at least in part on theinformation received from the source cell, such that a random accessresponse (RAR) transmitted to the relay node occurs on a downlinkbackhaul subframe corresponding to the relay node.
 11. The target cellof claim 10, wherein the processor is further configured to determine anallocation of access subframes and backhaul subframes corresponding tothe relay node that substantially preserves the access/backhaul resourcepartitioning utilized by the source cell for the relay node.
 12. Thetarget cell of claim 10, wherein the processor is further configured todetermine an allocation of access subframes and backhaul subframescorresponding to the relay node such that an assigned random accesschannel (RACH) occasion associated with the relay node occurs on anuplink backhaul subframe corresponding to the relay node.
 13. The targetcell of claim 10, wherein the processor is further configured todetermine an allocation of access subframes and backhaul subframescorresponding to the relay node such that respective non-MultimediaBroadcast over Single-Frequency Network (MBSFN) subframes correspondingto the relay node are allocated as access subframes.
 14. The target cellof claim 10, wherein the processor is further configured to transmitinformation to the relay node that relates to the allocation of accesssubframes and backhaul subframes corresponding to the relay node. 15.The target cell of claim 14, wherein the processor is further configuredto transmit the information to the relay node via unicast layer 3 (L3)signaling during the requested handover of the relay node or after therequested handover of the relay node.
 16. A target cell, comprising:means for receiving information, from a source Evolved Node B (eNB) inresponse to a requested handover of a relay node from the source eNB tothe target cell, relating to a partitioning of access resources andbackhaul resources utilized by the source eNB for the relay node; andmeans for allocating access resources and backhaul resources for therelay node, based at least in part on the information received from thesource eNB, wherein the means for allocating comprises means forallocating access resources and backhaul resources for the relay nodesuch that a random access response (RAR) transmitted to the relay nodeoccurs on a downlink backhaul subframe corresponding to the relay node.17. The target cell of claim 16, wherein the means for allocatingcomprises means for allocating access resources and backhaul resourcesfor the relay node such that an assigned random access channel (RACH)occasion associated with the relay node occurs on an uplink backhaulsubframe corresponding to the relay node.
 18. The target cell of claim16, wherein the means for allocating comprises means for allocatingaccess resources and backhaul resources for the relay node such thatrespective non-Multimedia Broadcast over Single-Frequency Network(MBSFN) subframes corresponding to the relay node are allocated asaccess subframes.
 19. The target cell of claim 16, further comprisingmeans for communicating information to the relay node that indicates theaccess resources and backhaul resources for the relay node.
 20. Acomputer program product, comprising: a non-transitory computer-readablemedium, comprising: code for causing a computer to receive information,from a source Evolved Node B (eNB) in response to a requested handoverof a relay node from the source eNB to a target cell, relating to apartitioning of access resources and backhaul resources utilized by thesource eNB for the relay node; and code for causing a computer toallocate access resources and backhaul resources for the relay node,based at least in part on the information received from the source eNB,such that a random access response (RAR) transmitted to the relay nodeoccurs on a downlink backhaul subframe corresponding to the relay node.21. A method performed by a relay node, comprising: identifying anallocation of access subframes and backhaul subframes associated withrelay communication; initializing a handover of the relay node from asource Evolved Node B (eNB) to a destination eNB; obtaining informationrelating to an access/backhaul subframe allocation utilized by thedestination eNB; and adjusting one or more subframes in the allocationof access subframes and backhaul subframes, based on the access/backhaulsubframe allocation utilized by the destination eNB, such that a randomaccess response (RAR) transmitted by the destination eNB occurs on adownlink backhaul subframe.
 22. The method of claim 21, wherein theadjusting comprises adjusting one or more subframes in the allocation ofaccess subframes and backhaul subframes prior to the handover.
 23. Themethod of claim 21, wherein the adjusting comprises adjusting one ormore subframes in the allocation of access subframes and backhaulsubframes in response to a random access channel (RACH) allocationutilized by the destination eNB.
 24. The method of claim 23, wherein theadjusting further comprises adjusting one or more subframes in theallocation of access subframes and backhaul subframes such that a RACHoccasion assigned by the destination eNB occurs on an uplink backhaulsubframe with the destination eNB.
 25. The method of claim 21, whereinthe adjusting comprises adjusting one or more subframes in theallocation of access subframes and backhaul subframes to facilitatesubstantial conformance with the access/backhaul subframe allocationutilized by the destination eNB.
 26. The method of claim 21, furthercomprising indicating a result of the adjusting to one or more serveduser equipment units (UEs).
 27. The method of claim 21, wherein theadjusting comprises adjusting one or more subframes in the allocation ofaccess subframes and backhaul subframes such that respectivenon-Multimedia Broadcast over Single-Frequency Network (MBSFN) subframesare allocated as access subframes.
 28. A relay node, comprising: amemory that stores data relating to a source Evolved Node B (eNB) and adestination eNB; and a processor configured to identify an allocation ofaccess subframes and backhaul subframes associated with relaycommunication, to initialize a handover of the relay node from thesource eNB to the destination eNB, to obtain information relating to anaccess/backhaul subframe allocation utilized by the destination eNB, andto adjust one or more subframes in the allocation of access subframesand backhaul subframes, based on the access/backhaul subframe allocationutilized by the destination eNB, such that a random access response(RAR) transmitted by the destination eNB occurs on a downlink backhaulsubframe.
 29. The relay node of claim 28, wherein the processor isfurther configured to adjust one or more subframes in the allocation ofaccess subframes and backhaul subframes in response to a random accesschannel (RACH) allocation utilized by the destination eNB.
 30. The relaynode of claim 29, wherein the processor is further configured to adjustone or more subframes in the allocation of access subframes and backhaulsubframes such that a RACH occasion assigned by the destination eNBoccurs on an uplink backhaul subframe with the destination eNB.
 31. Therelay node of claim 28, wherein the processor is further configured toadjust one or more subframes in the allocation of access subframes andbackhaul subframes such that respective non-Multimedia Broadcast overSingle-Frequency Network (MBSFN) subframes are allocated as accesssubframes.
 32. A relay node, comprising: means for identifying anallocation of access resources and backhaul resources associated withrelay communication; means for initializing a relay handover of therelay node from a source cell to a target cell; and means for adjustingat least a portion of the allocation of access resources and backhaulresources, based on an access/backhaul resource partitioning associatedwith the target cell, such that a random access response (RAR)transmitted by the target cell occurs on a downlink backhaul subframe.33. The relay node of claim 32, wherein the means for adjustingcomprises means for adjusting at least a portion of the allocation ofaccess resources and backhaul resources such that a random accesschannel (RACH) occasion assigned by the target cell occurs on an uplinkbackhaul subframe with the target cell.
 34. The relay node of claim 32,wherein the means for adjusting comprises means for adjusting at least aportion of the allocation of access resources and backhaul resourcessuch that respective non-Multimedia Broadcast over Single-FrequencyNetwork (MBSFN) subframes are allocated as access subframes.
 35. Acomputer program product, comprising: a non-transitory computer-readablemedium, comprising: code for causing a computer to identify anallocation of access resources and backhaul resources associated withrelay communication; code for causing a computer to initialize a relayhandover of a relay node from a source cell to a target cell; and codefor causing a computer to adjust at least a portion of the allocation ofaccess resources and backhaul resources, based on an access/backhaulresource partitioning associated with the target cell, such that arandom access response (RAR) transmitted by the target cell occurs on adownlink backhaul subframe.